Unit Conversion & Significant Figures: Crash Course Chemistry #2

How is the standard kilogram defined?

• The mass of a specific platinum-iridium cylinder.

• The mass of one liter of water.

• The mass of an average human.

• The mass of a specific amount of carbon atoms.

How many base units are included in the International System of Units (SI)?

• 5

• 7

• 10

• 12

Which of the following is a derived unit in the International System of Units?

• Meter

• Kilogram

• Newton

• Second

What was the main reason for the failure of the Mars Climate Orbiter mission?

• A software malfunction.

• Incorrect calculations due to unit mismatch.

• A collision with space debris.

• Insufficient fuel for the mission.

Which of the following is an example of an exact number?

• The weight of a bag of apples.

• The number of students in a classroom.

• The temperature of a room.

• The length of a pencil.

Why do measured numbers, like a car's speed, always have limited precision?

• The object being measured is constantly changing.

• The measuring tool has limits to its accuracy.

• It is too difficult to write down all the decimal places.

• The number is rounded for simplicity.

What is the main purpose of using significant figures in scientific measurements?

• To make calculations faster.

• To show only the digits that are certain and reliable.

• To avoid using decimal points.

• To make numbers look more impressive.

How does scientific notation help clarify the number of significant figures in a measurement?

• It removes all non-zero digits.

• It always shows exactly two significant figures.

• It makes it clear which zeros are part of the measurement's precision.

• It converts all numbers into whole numbers.